Funding is requested to continue support of the inter-departmental Center at Vanderbilt and its program, which is oriented towards augmenting programs related to aspects of molecular toxicology. The Center functions through the following units: Center Investigators, Director's Office, Technical Services, Clerical and Accounting, Analytical Chemistry and Spectroscopy, Metals Analysis, Natural Products, Enzymology and Cell Culture, Cytoanalysis and Molecular Genetics, and Pilot Projects. These units provide portions of salary support for eight named Center Investigators and are intended to support ongoing research projects by Center Investigators and others at Vanderbilt with interests in toxicology by providing key instrumentation and expertise as opposed to direct research project support (with the exception of Pilot Projects). The Center brings together scientists with interests in toxicology having expertise in structural, synthetic, and mechanistic chemistry, mechanistic bio-organic chemistry, mycology, metals toxicology, enzymology, biochemical regulation, cell culture, chromatin structure, chemical carcinogenesis, drug toxicity, gene expression, and DNA repair. These programs involve a number of individuals at Vanderbilt in addition to the eight named Center Investigators, and arrangements allow for review of Center programs within the University and from outside. The research is oriented toward the general goals of 1) understanding phenomena of toxicological interest in chemical terms, 2) understanding toxicological problems at biological and biochemical levels, and 3) applying this knowledge to human situations.